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All Good Things, Even the Shuttle, Must End

by

Donald F. Robertson

I
have always been a staunch defender of the Space Shuttle. Almost as
far back as I can remember, observing, studying, and advocating for
this project has been an important part of my life. It is difficult
for many in my generation to even imagine a future without the
shuttle project.

The
time has finally come to dust off our imaginations and envision just
such a future.

Like most good things, the Shuttle is
a vehicle
for promises only partially fulfilled. Those who fly the Shuttle
attest that, once in space, it is a craft of amazing grace and power.
Astronauts state it is rock-solid stable and can be positioned with
near-perfect precision. The trouble is, too many compromises were
made to get the design off the drawing boards and none of that grace
is apparent getting into, or out of, orbit.

Along
with many others I argued that, in the long term, reusability was the
key to lower launch costs. As a first generation vehicle, it is not
surprising that the Shuttle failed to fulfill all of its promises. It
provided valuable operational experience, it kind-of worked, and
there was no replacement on the political horizon. We should
persevere and, if we only try hard enough, we can _make_ the Shuttle
perform.

In
the days before Columbia was lost, I was writing an article proposing
the use of surplus Shuttle capacity to start a lunar base. The
Shuttle launch system, I argued, was capable of maybe ten flights per
year and we were using it less than five. If we were maintaining the
Shuttle anyway, the unused capacity of some 150,000 kilograms of
payload to orbit each year could go a long way toward testing a new
lunar transportation system and pre-positioning some equipment for
future missions on Earth’s moon -- without developing any new
launch vehicles. Since the majority of the shuttle’s cost was
involved in maintaining the orbiters and infrastructure, and not in
actual flight operations, the additional flights would not add all
that much to the total cost of the Shuttle program. The only new
developments would be a trans-Lunar stage and a lander, both of which
would be needed later when the lunar base was being fully deployed.

Like
the Shuttle program itself, now that article will never be completed.

With
the loss of Columbia, circumstances changed, and the Shuttle was
given a 2010 death sentence in order to avoid the high costs of
“re-certifying” these ancient vehicles for
continued flight. It
made more sense to invest the money “going forward to the
past”,
as space analyst Tim Kyger put it. NASA would finish the Space
Station with the last Shuttle flights while developing a
“quick-and-dirty” Apollo-like capsule to return to
Earth’s moon
and prepare to go to Mars. After decades following the ever-receding
mirage of inexpensive access to orbit, it was time to refocus on the
reason for it all: to “explore strange new worlds and go
where no
one has gone before.”

With
the latest problems safely launching the Shuttle, circumstances have
changed yet again. If the fix to prevent the External Tank from
shedding insulation is not obvious and quick -- and possibly even if
it is -- it is finally time to give up on the Shuttle.

There,
I said it: maybe the Shuttle should never fly again. It is very
hard to write those words, but truth and ease are rarely synonymous. We
have learned to do many things from this rickety vehicle -- and
how not to do many more -- but we have learned all we can from the
Shuttle.

Where
does that leave the Space Station?

I
believe that the Space Station -- or something else in space that
requires regular deliveries of cargo -- is vital if we are to have a
near-term future as a spacefaring people. Without a base in space,
there is no near-term market to justify new rockets and the launch
industry could wither. With no launch industry, obviously, there is
no spaceflight. Since the Space Station is already built and
partially deployed, it makes no sense at this point to start over.

Discovery’s
problems may turn out to be a blessing in disguise. By taking the
Shuttle -- a vehicle that clearly has no future -- and its giant
payload out of the loop, the Space Station may become entirely
dependent on SpaceX, Kistler, the Evolved Expendable Launch Vehicles,
Ariane, and others yet to come along. All these vehicles could have
a future – but only if they have a market.

It
is unfortunate that the Shuttle project ran out of steam with much of
the Space Station’s hardware still on the ground. While the
current Station configuration is clearly capable of long-term flight,
and thus of being the market commercial rockets need, it is time to
revisit the idea of getting at least the European and Japanese
hardware into orbit on the EELVs.

The
empty European Columbus module weighs some 10,300 kilograms, about
half the 21,892 kilogram payload of a Delta-IV Heavy to the Space
Station’s orbit. In the configuration that was to be launched
by
the Shuttle, Columbus weighs 12,000 kilograms. At 4.477 meters, the
widest diameter is comfortably smaller than the advertised five-meter
diameter of the largest Delta-IV payload shroud. Much the same is
true of the Japanese Kibo module, which has a dry weight of 15,900
kilograms and a size of 4.4 x 4.2 x 11.2 meters. The most
significant problem would be presented by Japan’s external
experiment platform for the Space Station, which measures 5.0 x 4.0 x
5.6 meters but only weighs four tons. It is true that these modules
were designed to be mounted horizontally in the Shuttle’s
payload
bay, but even on the Shuttle they would be launched vertically; they
have to be capable of significant vertical loads.

If
most or all of the remaining Shuttle payloads could be launched on
existing expendable rockets, the Shuttle program could be shut down
tomorrow, or possibly after one more repair mission to the
politically and scientifically important Hubble Space Telescope. Much
of the $5 billion a year the Space Shuttle costs could be
funneled into the Crew Exploration Vehicle, developing a
Shuttle-derived heavy lift vehicle, deep space propulsion, and early
work on a lunar base -- and probably still have money to spare.

NASA
does seem to have caught the religion. NASA Administrator Michael
Griffin was quoted in the trade journal Space News: “It is in
our
interest to sponsor commercial development [of launch vehicles] by
providing the only market I have for the next few years, which is
cargo delivery to the Station.”

If
he means it, and if the storied Space Shuttle really is down for the
count, maybe all the years and dollars entrepreneurs have bet on
innovative launch vehicles will finally pay off.

The
death of a great dream is bound to be painful, but when new life
follows death it usually starts out small. Spring is in the air. Let
one rocket die so that a hundred rockets can fly. . . .